I. Field of the Invention
The invention is directed generally to a multiaxial interconnection apparatus for transducers and, more particularly, to a multiaxial transducer interconnection apparatus for use in advanced rate adaptive cardiac pacemaker systems, defibrillators, cardioverters, heart monitors, metabolic need indicators and similar medical electronic devices.
II. Discussion of the Prior Art
Heart and respiration activity generates mechanical energy. This energy propagates through the body and can be detected by appropriate transducers and may provide information useful for the control of organ functions such as heart rate pacing, for example. Current transducer technology does not address certain critical aspects of such medical electronics applications.
Some prior approaches in the medical electronics art use active (piezoelectric) transducer elements which are well known such as Bruel & Kjaer Company's Type 4321 and Endevco Company's Model 2258-10/-100 devices. These devices are limited in their application, however, because they do not utilize the cost and size advantages of micromachining technology.
Passive transducers are also known in the prior art. Passive transducers require excitation energy to operate. In the case of a multiaxial transducer, the number of supply lines is proportional to the number of uniaxial transducer components assembled together. The reduction in quantity of transducer terminals or wires is critical for many applications. A number of companies offer passive (piezoresistive) transducers such as IC Sensors, 1701 McCarthy Boulevard, Mulpitas, Cal., for example. These devices are sensitive in one dimension only, but could be integrated into a multiaxial transducer. However, it is believed that the die substrates currently utilized in the industry, have no designed-in features to aid in substrate-to-substrate electrical connection.
This invention provides a multiaxial transducer, useful for medical electronics applications, comprising transducer elements mounted on electrically interconnected modular substrates. The multiaxial transducer of the invention achieves a reduction in the quantity of terminals required for many applications as compared to other known devices. A multiaxial transducer interconnection apparatus is disclosed. The apparatus comprises first, second and third substrate modules each having a plurality of electrical tracks thereon. A portion of the electrical tracks is structured and arranged to interconnect the substrate modules in an orthogonal relationship to each other. The plurality of tracks on each substrate module is further arranged to form a pattern identical to the plurality of tracks on the other substrate modules. The substrate modules each include a mounting region whereon transducer die elements are mounted. The apparatus disclosed in the invention may be used in an improved advanced rate adaptive heart pacemaker system including a multiaxial transducer as disclosed by the invention as a sensing component of such a system.
One alternate embodiment of the invention includes a base upon which the modules would mount. Another alternate embodiment of the invention employs a chip carrier to support the multiaxial transducer of the invention.